1. Field of the Invention
The present invention relates to a plasma display panel, and more particularly, to a plasma display panel in which a plasma discharge is induced by a facing discharge of electrodes disposed to face each other.
2. Description of the Related Art
Generally, a plasma display panel (hereinafter, referred to as ‘PDP’) is a display device in which vacuum ultraviolet rays are emitted from plasma by gas discharge to excite phosphors to generate visible light, thereby displaying images. In such a PDP, a large screen of 60 inches or more can be implemented with a thickness of no more than 10 cm. Further, the PDP is a self-emitting device, like the CRT, that reproduces superior color without distortion and has a large viewing angle. In addition, due to its simple manufacturing process, the PDP has an advantage over the LCD or the like in view of productivity and cost and thus has been spotlighted as a next-generation industrial flat panel display and a home TV display.
The structure of the PDP has been developed since the 1970s, and at present time, a three-electrode surface-discharge type structure is generally used. In the three-electrode surface-discharge type structure, a front substrate has a pair of electrodes disposed on the same surface, and a rear substrate is spaced at a predetermined distance from the front substrate. The rear substrate has an address electrode extending to intersect the pair of electrodes. A discharge gas is sealed between the front substrate and the rear substrate. In general, whether the sustain discharge occurs is determined by the address discharge between scan electrodes, which are connected to lines, respectively, and which are controlled independently, and address electrodes that are disposed to face the scan electrodes. A sustain discharge proportionate to display brightness is performed by the pair of electrodes on the front substrate.
Meanwhile, the PDPs that are now available on the market may have the resolution of XGA 1024×768 in a 42-inch size. In the end, there is a need for display devices that can display an image of a full-HD (High Definition) level. In a PDP, in order to display the image of the full-HD level (1920×1080), the size of each discharge cell should be reduced. In other words, the discharge cells are disposed with high density.
In the PDP having the three-electrode surface-discharge type structure, a reduction in size of the discharge cell means a reduction in length and area of an electrode. This may result in a reduction in brightness and efficiency of the PDP and increase in a discharge firing voltage. Thus, with the PDP having the high density, there has been a need for a structure different from the structure in which an address discharge is generated by a facing discharge and in which a sustain discharge is generated by a surface discharge.
Meanwhile, FIG. 11 is a graph showing the changes in discharge firing voltage in a surface discharge type electrode structure and a facing discharge type electrode structure while changing the partial pressure of a xenon gas having superior discharge efficiency. In this experiment, a discharge gap between electrodes of the surface discharge type electrode structure is set to 60 μm, a discharge gap between electrodes of the facing discharge type electrode structure is set to 250 μm, and an internal pressure is set to 450 Torr.
These experiment results will now be examined considering the fact that the discharge firing voltage is proportional to the partial pressure of the discharge gas and the distance between the electrodes. Even though there was the difference of about 190 μm in the discharge gap, there was only a difference of about 20 V in the discharge firing voltage. This means that the facing discharge type electrode structure may be more advantageous than the surface discharge type electrode structure when using a plasma discharge.